During interventions, for diagnosis purposes, treatment planning or outcome control of an intervention, it is known to visualise the left and right coronary arteries partly surrounding the heart by using X-ray image generating devices of the so-called C-type. The visualisation is usually based on a reconstruction of the coronary arteries by the means of at least two acquired images. For acquisition, the left or the right branch of the coronary arteries (LCA or RCA) are selectively injected with a contrast agent. In other words, images are acquired for the left branch separately from the acquisition of the images of the right branch. Usually the acquisitions are analysed independently for a diagnosis on the whole coronary artery tree. But it has shown that this provides inadequate information to the user, i.e., for example, a surgeon or cardiologist. However, a need may exist to provide comprehensive information about the current coronary artery situation.